The STA-SAF System

The
Sta-Saf system combines six Rupture Disk (Bursting Disc) types and three safety head
options that provide the user with extended service life reverse buckling
disk technology in sizes from 1"/25mm to 36"/900mm at burst pressures
ranging from 5 psi/0.34 bar to 2000 psi/137.9
bar.

This catalog describes the types JRS™, S-90™, RLS™, and
FRS™ Rupture Disks and their Safety Head (holder) options. The most
extensive size and set pressure capability is offered through these widely
applied designs that are in service in well over 50,000 installations
worldwide.

The most capable Sta-Saf technologies, SKR™
& Sigma™ Rupture Disks, have their own dedicated catalogs (77-4003 and
77-4011 respectively).

Standard
Features of the
STA-SAF® Family

STA-SAF®
Rupture Disks:

90%
or greater operating ratio

Vacuum resistant

Solid
metal construction enabling optimum leak tightness

Designed for non-fragmentation

Recommended for isolation of pressure relief valves

Metal
tag with product identification and traceability data, as well as code
symbol stamps as appropriate

STA-SAF®
Safety Heads:

Disk
dome shielded by safety head inlet for all sizes

Locating pins ensure centering and correct orientation of the
disk within the safety head

Spiral groove with 125-250 AARH finish on both inlet and outlet
safety head external mating surfaces to enhance gasket
performance

Rupture
Disk

Use In Safety Head
Type

S90

SRB-7RS, SRB-7FS,
S90-7R

JRS

SRB-7RS and
SRB-7FS

FRS

SRB-7RS, SRB-7FS,
S90-7R

RLS

SRB-7RS and
SRB-7FS

STA-SAF®
Rupture Disk (Bursting Disc) Material Options

Standard
materials and their maximum recommended service temperatures for the
Sta-Saf range of Rupture Disks are:

Material

Disk Types

Maximum Recommended
Temperature

Nickel (alloy 200)

S-90, RLS, JRS, FRS, SKR, Sigma

750° F

399° C

Monel® (alloy 400)

S-90, RLS, JRS, FRS, SKR, Sigma

900° F

482° C

Inconel® (alloy 600)

S-90, RLS, JRS, FRS, SKR, Sigma

1100° F

593° C

Stainless Steel

S-90, RLS, JRS, FRS, SKR, Sigma

750° F

400° C

Hastelloy® C-276 (alloy C-276)

S-90, RLS, JRS, SKR, Sigma

900° F

482° C

Tantalum

RLS, SKR

500° F

260° C

Titanium

SKR

572° F

300° C

Aluminum

S-90

250° F

120° C

Fluoropolymer Film Liners (TEF)

S-90, RLS, JRS, FRS, SKR, Sigma

500° F

260°
C

For each
material the upper temperature limit has been determined from the
recommendations of material manufacturers and user experience. Rupture
disk technology uses Nickel and its alloys to provide the user with a
range of excellent corrosion resistance, and thermal stability
particularly in the case of alloy 600.

Hastelloy is a trademark of Haynes International Inc., Monel and
Inconel are trademarks of Inco Alloys International, Inc. BS&B may use
equivalent materials from other sources.

Fluoropolymer film liners are available as an additional corrosion
barrier with most Sta-Saf Rupture Disks. Order as "TEF LINER" when
required. Liners are applied to the inlet/process side of the Rupture
Disk, unless otherwise agreed.

This
wide material range provides the user with options in the selection of a
Rupture Disk (Bursting Disc) material that is resistant to the process media. Corrosion of
disk material will affect performance and may result in premature burst or
leakage through the disk.

Operating
Pressure Ratio

Sta-Saf
reverse buckling Rupture Disks can be operated to 90% of their marked
burst pressure (or to 95% of their minimum burst pressure) for burst
pressures of 40 psi (2.76
bar) and higher.

For
lower burst pressures, the operating pressure ratio is 90% of minimum
burst pressure. For applications that demand a closer relationship between
operating pressure and burst pressure, select type Sigma EXL™ (see catalog
77-4011) which can operate up to 100% of minimum burst
pressure.

Differential
Pressure

Rupture
disks respond to differential pressure. Please take into account the
service conditions at the inlet and outlet of a Rupture Disk (Bursting Disc) when
completing specifications.

Burst
Pressure Tolerances

All of
the Sta-Saf Rupture Disks offer the same tolerance considerations when
completing a specification. Whether the ASME/North American or
European/ISO approach to burst pressure and tolerance is used, BS&B
applies both a burst tolerance and an optional manufacturing design range.

Burst
tolerance is the +/- range
of pressure over which a Rupture Disk (Bursting Disc) can be expected to burst. Burst
tolerance is either +/-5% of burst pressure or +/- 2 psi (+/-0.138 bar) for disks rated
below 40 psi (2.76
bar).

Manufacturing design range is a range of pressure, always
applied to the minus side of the user requested burst pressure for Sta-Saf
Rupture Disks, that simplifies disk fabrication testing and provides
economic benefit to the user where such an added tolerance can be
accommodated by the application.

MDR= 0: where the user requires the tightest margin
between normal service pressure and burst pressure, a zero range disk
shall be used.

MDR= -5%: applied to the requested burst pressure, a -5%
range allows an additional 5% tolerance applied on the minus side of the
user requested burst pressure.

MDR= -10%: applied to the requested burst pressure, a -10%
range allows an additional 10% tolerance applied on the minus side of
the user requested burst pressure.

Note:
MDR and burst tolerance are additive. In the European/ISO case, the burst
tolerance and MDR are simply combined. In the ASME case, the 'marked burst
pressure' for a lot of Rupture Disks must be a value within the agreed
manufacturing design range and then the burst tolerance is
applied.

The two-step
approach to set pressure specification:

1.
Decide between ASME/North American (with or without 'UD' stamp) and
European (with or without 'CE' mark) / ISO standards.
2. Select the
manufacturing design range appropriate to the application and check that
it is available for the disk type selected.
(0, -5 or -10%)

Pressure/Temperature
Relationship

The
burst pressure of all Rupture Disks is partially determined by the
physical properties of the material employed. Tensile strength will vary
with temperature, which leads to variation in burst pressure. Reverse
buckling technology is the least sensitive to temperature variations and
is used by all Sta-Saf Rupture Disks. However, for the highest accuracy of
performance, BS&B certifies Sta-Saf Rupture Disks by testing at the
users’ chosen burst temperature.

Where
operating pressure and temperature may rise rapidly, the user should
carefully select the temperature of the Rupture Disk (Bursting Disc). BS&B can provide
advice for such applications. Inconel (alloy 600) provides excellent
thermal stability for applications that experience a wide range of service
temperatures at which over-pressure might occur.

The
burst pressure of each lot of Sta-Saf Rupture Disks is tested at the users
specified temperature (burst temperature). Should the disk be rated above
or below ambient temperature, burst testing for product certification
shall be conducted at this coincident burst temperature to ensure the best
product accuracy. For applications which have operating temperatures that
may exceed the burst temperature, please review with BS&B Safety
Systems, Inc. or BS&B Safety Systems, Ltd.

KR: Flow
Resistance Factor

Flow
resistance factor "KR" may be used to determine the relieving
capacity of a system when using techniques such as those described in
Crane Technical Paper No. 410.

Individual KR values have been established for both gas
& liquid service, where appropriate, for Sta-Saf Rupture Disks. Care
must be taken to use the correct value for sizing purposes.

When
KR values are marked on Sta-Saf Rupture Disk (Bursting Disc) tags, those for
gas service are shown as KRg or KR (GAS), and those
for liquid service are shown as KRl or KR (LIQ).
When using KR value for sizing calculations, the nominal pipe
size (assuming schedule 40 pipe) of the vent system is used. When using
'coefficient of discharge' sizing techniques, the Minimum Net Flow Area
(MNFA) or Net Relief Area (NRA) of the Rupture Disk (Bursting Disc) device is used.

You can
obtain MNFA and NRA values at our website at www.bsbsystems.com or from
our sales representatives and distributors.

Installation

The
Sta-Saf family of Rupture Disk (Bursting Disc) devices is designed for installation
between pipe flanges. Compatibility with all international flange
standards is available, including: ANSI, DIN, JIS, BS, ISO, AFNOR and UNI.
Between the Safety Head and the pipe flanges an application compatible
gasket is used for sealing purposes.

The
unique configuration of the SRB-7RS Safety Head design enables the same
holder to be installed between flanges covering a range of flange
specifications. For example: a single design of 1"/25mm SRB-7RS Safety
Head is compatible with ANSI 150/300/600, DIN PN10/16/25/40, and JIS
PN10/16/20/30/40 flanges. This will reduce the inventory of Safety Heads
required by the user, and provide simplicity of common installation
practices.

Code
Compliance

The
Sta-Saf family of products is designed to meet the requirements of the
international Rupture Disk (Bursting Disc) standards.
Certification to the following
codes is available:
ASME Section VIII (including 'UD' stamp) and
Section III
CEN ISO 4126 part2 (pending); ‘CE’ Mark
ISO 6718,
BS2915, SVTI, Stoomwezen
TUV AD Merkblatt A1
The Sta-Saf family of
Rupture Disk (Bursting Disc) devices is compliant with API RP520 Part 1
recommendations.

Double Disk
Assemblies

Double
disk assemblies consist of three flange components, an inlet, a mid-flange
and an outlet flange with a second disk between the mid-flange and outlet
flange. The SRB-7RS Safety Head and the S90-7R Safety Head are available
as double disk assemblies.

Applications:

1.
Prevention of leakage of corrosive, toxic or expensive process materials
and disk service life extension in continuous processes. The first disk
isolates and protects the second disk from a corrosive process medium.
Leakage caused by fatigue or corrosion through the first disk will be
prevented from escaping by the second disk. Maintenance replacement can be
through a planned shutdown. (Use of a tell-tale assembly between the two
Rupture Disks is required.)

2.
Elimination of back pressure - the second Rupture Disk (Bursting Disc) withstands the
system back pressure, isolating the first disk. Any change in pressure
differential across the first disk induced by back pressure is eliminated
and it will rupture at its rated burst pressure. (The second Rupture Disk (Bursting Disc)
may be rated at a lower burst pressure to compensate for the maximum back
pressure that may coincide with a burst condition).

3. Quick
Opening Valve. The volume between the two disks is pressurized. The
evacuation of this pressure causes both disks to rupture virtually
simultaneously providing an immediate full relief opening when the inlet
pressure exceeds the disk burst pressure.

Optional TEF liners to enhance corrosion resistance (on the
inlet/process and/or down-stream side of the disk). Order as “TEF Liner”
or identify special material requirements

Disk Material

Disk Size

Aluminum (Al)

Nickel Alloy 200 (Ni)

Hastelloy® Alloy C-276 (Hast C-276) & 316 Stainless
(316SS)

in

mm

Min.

Max.

Min.

Max.

Min.

Max.

psig

barg

psig

barg

psig

barg

psig

barg

psig

barg

psig

barg

1

25

75

5.17

125

8.61

125

8.62

1000

68.9

328

22.6

1000

68.9

1.5

40

54

3.72

90

6.2

90

6.21

1000

68.9

282

19.4

1000

68.9

2

50

45

3.1

75

5.17

75

5.17

1000

68.9

230

15.9

1000

68.9

3

80

36

2.48

60

4.14

60

4.14

1000

68.9

167

11.5

1000

68.9

4

100

30

2.06

50

3.45

50

3.45

800

55.2

132

9.10

800

55.2

6

150

24

1.65

40

2.76

40

2.76

800

55.2

92

6.34

800

55.2

8

200

n.a.

n.a.

n.a.

n.a.

35

2.41

700

48.3

n.a.

n.a.

n.a.

n.a.

10

250

n.a.

n.a.

n.a.

n.a.

30

2.07

700

48.3

n.a.

n.a.

n.a.

n.a.

12

300

n.a.

n.a.

n.a.

n.a.

27

1.87

600

41.4

n.a.

n.a.

n.a.

n.a.

14

350

n.a.

n.a.

n.a.

n.a.

25

1.72

500

34.5

n.a.

n.a.

n.a.

n.a.

16

400

n.a.

n.a.

n.a.

n.a.

23

1.59

100

6.89

n.a.

n.a.

n.a.

n.a.

18

450

n.a.

n.a.

n.a.

n.a.

22

1.52

92

6.34

n.a.

n.a.

n.a.

n.a.

20

500

n.a.

n.a.

n.a.

n.a.

21

1.45

84

5.79

n.a.

n.a.

n.a.

n.a.

24

600

n.a.

n.a.

n.a.

n.a.

20

1.38

70

4.82

n.a.

n.a.

n.a.

n.a.

30

750

n.a.

n.a.

n.a.

n.a.

20

1.38

70

4.82

n.a.

n.a.

n.a.

n.a.

US
Patent numbers: 4441350, 4481850 and other international patents apply.
TEF liners available at all burst pressures. For burst pressures below
S-90 minimums use the JRS, FRS, SKR or Sigma type disks. For pressures
above the S-90 maximums use the RLS disk or the S90-HP (contact BS&B
Safety Systems Inc. or BS&B Safety Systems Limited for details).
Hastelloy is a trademark of Haynes International Inc., Monel and Inconel
are trademarks of Inco Alloys International, Inc.

Disk Material

Disk Size

Inconel® Alloy 600 (Inc)

Monel® Alloy 400 (Mon)

in

mm

Min.

Max.

Min.

Max.

psig

barg

psig

barg

psig

barg

psig

barg

1

25

150

10.3

1000

68.9

150

10.3

1000

68.9

1.5

40

110

7.58

1000

68.9

110

7.58

1000

68.9

2

50

90

6.21

1000

68.9

90

6.21

1000

68.9

3

80

72

4.96

1000

68.9

72

4.96

1000

68.9

4

100

60

4.14

800

55.2

60

4.14

800

55.2

6

150

48

3.31

800

55.2

48

3.31

800

55.2

8

200

42

2.89

700

48.3

42

2.89

700

48.3

10

250

36

2.48

700

48.3

36

2.48

700

48.3

12

300

33

2.28

600

41.4

33

2.28

600

41.4

14

350

30

2.07

500

34.5

30

2.07

500

34.5

16

400

28

1.93

180

12.4

28

1.93

180

12.4

18

450

26

1.79

160

11.0

26

1.79

160

11.0

20

500

24

1.65

142

9.79

24

1.65

142

9.79

24

600

22

1.52

118

8.14

22

1.52

118

8.14

30

750

20

1.38

80

5.52

20

1.38

80

5.52

US
Patent numbers: 4441350, 4481850 and other international patents apply.
TEF liners available at all burst pressures. For burst pressures below
S-90 minimums use the JRS, FRS, SKR or Sigma type disks. For pressures
above the S-90 maximums use the RLS disk or the S90-HP (contact BS&B
Safety Systems Inc. or BS&B Safety Systems Limited for details).
Hastelloy is a trademark of Haynes International Inc., Monel and Inconel
are trademarks of Inco Alloys International, Inc.

The RLS
is a Precision Circular-Scored Reverse Buckling Rupture Disk (Bursting Disc). When
over-pressurized, this domed, solid metal, reverse buckling disk reverses
and opens along a pre-weakened circular score line on the down-stream side
of the disk. A patented hinge welded to the disk facilitates relief
opening along the score line and retains the disk’s central petal
preventing fragmentation even at high burst pressures.

Gas
and full liquid service

Designed for non-fragmentation

Withstands full vacuum and back pressure equal to or less than
burst pressure (higher upon request)

Suitable for operating pressure to 90% of the marked burst
pressure and 95% of the minimum burst pressure (CEN ISO 4126-2 Standard
pending)

Damage safety ratio 1.5. A damaged RLS disk will burst at or
below 1.5 times its marked burst pressure

Optional TEF liner on the process and/or down-stream side of the
disk. Order as “TEF Liner” or identify special requirements

Disk Material

Disk Size

Tantalum

Nickel Alloy 200

Hastelloy® Alloy C-276 & 316 Stainless

in

mm

Min.

Max.

Min.

Max.

Min.

Max.

psig

barg

psig

barg

psig

barg

psig

barg

psig

barg

psig

barg

1

25

125

8.62

2000

137.9

125

8.62

2000

137.9

175

12.07

2000

137.9

1.5

40

85

5.86

1800

124.1

85

5.86

1800

124.1

145

10

1800

124.1

2

50

70

4.83

1800

124.1

70

4.83

1800

124.1

115

7.93

1800

124.1

3

80

55

3.79

1600

110.3

55

3.79

1600

110.3

75

5.17

1600

110.3

4

100

45

3.10

1050

72.4

45

3.10

1050

72.4

65

4.48

1050

72.4

6

150

35

2.41

650

44.8

35

2.41

650

44.8

45

3.10

650

44.8

8

200

n.a.

n.a.

n.a.

n.a.

35

2.41

400

27.6

45

3.10

400

27.6

10

250

n.a.

n.a.

n.a.

n.a.

35

2.41

250

17.2

45

3.10

250

17.2

12

300

n.a.

n.a.

n.a.

n.a.

35

2.41

150

10.34

45

3.10

150

10.34

14

350

n.a.

n.a.

n.a.

n.a.

35

2.41

130

8.96

45

3.10

130

8.96

16

400

n.a.

n.a.

n.a.

n.a.

25

1.72

110

7.58

35

2.41

110

7.58

18

450

n.a.

n.a.

n.a.

n.a.

25

1.72

90

6.21

35

2.41

90

6.21

US
Patent number: 4,404,982 and other international patents.The hinge
attached to the disk is 316SS. TEF liners available at all burst
pressures. For burst pressures below RLS minimums use JRS, FRS,
SKR, Sigma or S-90 type disks. Hastelloy is a trademark of
Haynes International Inc., Monel and Inconel are trademarks of Inco Alloys
International, Inc.

Disk Material

Disk Size

Inconel® Alloy 600

Monel® Alloy 400

in

mm

Min.

Max.

Min.

Max.

psig

barg

psig

barg

psig

barg

psig

barg

1

25

150

10.3

2000

137.9

150

10.3

2000

137.9

1.5

40

105

7.24

1800

124.1

105

7.24

1800

124.1

2

50

85

5.86

1800

124.1

85

5.86

1800

124.1

3

80

65

4.48

1600

110.3

65

4.48

1600

110.3

4

100

55

3.79

1050

72.4

55

3.79

1050

72.40

6

150

40

2.76

650

44.8

40

2.76

650

44.8

8

200

40

2.76

400

27.6

40

2.76

400

27.6

10

250

40

2.76

250

17.2

40

2.76

250

17.2

12

300

40

2.76

150

10.34

40

2.76

150

10.3

14

350

40

2.76

130

8.96

40

2.76

130

8.96

16

400

30

2.07

110

7.58

30

2.07

110

7.58

18

450

30

2.07

90

6.21

30

2.07

90

6.21

US
Patent number: 4,404,982 and other international patents.The hinge
attached to the disk is 316SS. TEF liners available at all burst
pressures. For burst pressures below RLS minimums use JRS, FRS,
SKR, Sigma or S-90 type disks. Hastelloy is a trademark of
Haynes International Inc., Monel and Inconel are trademarks of Inco Alloys
International, Inc.

JRS™ Solid
Metal
Reverse Buckling Rupture Disk (Bursting Disc)

A domed,
solid metal low-pressure reverse buckling disk, the JRS reverses on
over-pressure and opens by cutting along a teeth ring attached to the
atmospheric side of the disk. A hinge integral to the teeth ring on the
downstream side of the disk retains the disk’s central petal preventing
fragmentation.

Designed for non-fragmentation

Withstands full vacuum and back pressure equal to or less than
burst pressure (higher upon request)

Suitable for operating pressure to 90% of the marked burst
pressure or 95% of the minimum burst pressure (CEN ISO 4126-2 Standard
pending)

Optional TEF liner on the process side of the disk. Order as “TEF
Liner” or identify special requirements

Disk Material

Disk
Size

Nickel Alloy 200

Inconel® Alloy 600

Monel® Alloy 400

in

mm

Min.

Max.

Min.

Max.

Min.

Max.

psig

barg

psig

barg

psig

barg

psig

barg

psig

barg

psig

barg

1

25

22

1.52

125

8.62

22

1.52

150

10.34

22

1.52

150

10.34

1.5

40

20

1.38

90

6.21

20

1.38

110

7.58

20

1.38

110

7.58

2

50

18

1.24

75

5.17

18

1.24

90

6.21

18

1.24

90

6.21

3

80

16

1.1

60

4.14

16

1.1

72

4.96

16

1.1

72

4.96

4

100

14

0.97

50

3.45

14

0.97

60

4.14

14

0.97

60

4.14

6

150

12

0.83

40

2.76

12

0.83

48

3.31

12

0.83

48

3.31

8

200

12

0.83

35

2.41

12

0.83

42

2.89

12

0.83

42

2.89

10

250

12

0.83

30

2.07

12

0.83

36

2.48

12

0.83

36

2.48

12

300

12

0.83

27

1.86

12

0.83

33

2.28

12

0.83

33

2.28

14

350

9

0.62

25

1.72

9

0.62

30

2.07

9

0.62

30

2.07

16

400

7

0.48

23

1.59

7

0.48

28

1.93

7

0.48

28

1.93

18

450

6

0.41

22

1.52

6

0.41

26

1.79

6

0.41

26

1.79

20

500

5

0.34

21

1.45

5

0.34

24

1.65

5

0.34

24

1.65

24

600

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

30

750

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

36

900

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

n.a.

US
Patent numbers: 4236648 and other international patents. TEF liner
available for disk sizes 2” and larger. JRS teeth ring attached to the
disk is 316SS. Other materials upon request. Minimum burst pressures are
applicable at all temperatures, maximum burst pressures are at 72°F
(32°C). For burst pressures below JRS minimums use the FRS type disk. For
Pressures above the JRS maximums use disk types S-90, RLS, SKR, and Sigma.
Hastelloy is a trademark of Haynes International Inc., Monel and Inconel
are trademarks of Inco Alloys International, Inc.

Disk Material

Disk
Size

316SS

Hastelloy® Alloy C-276

in

mm

Min.

Max.

Min.

Max.

psig

barg

psig

barg

psig

barg

psig

barg

1

25

24

1.65

180

12.41

24

1.65

180

12.41

1.5

40

22

1.52

150

10.34

22

1.52

150

10.34

2

50

20

1.38

120

8.27

20

1.38

120

8.27

3

80

18

1.24

80

5.52

18

1.24

80

5.52

4

100

16

1.1

70

4.83

16

1.1

70

4.83

6

150

14

0.97

50

3.45

14

0.97

50

3.45

8

200

12

0.83

42

2.89

12

0.83

42

2.89

10

250

12

0.83

36

2.48

n.a.

n.a.

n.a.

n.a.

12

300

12

0.83

33

2.28

n.a.

n.a.

n.a.

n.a.

14

350

9

0.62

30

2.07

n.a.

n.a.

n.a.

n.a.

16

400

7

0.48

28

1.93

n.a.

n.a.

n.a.

n.a.

18

450

6

0.41

26

1.79

n.a.

n.a.

n.a.

n.a.

20

500

5

0.34

24

1.65

n.a.

n.a.

n.a.

n.a.

24

600

5

0.34

22

1.52

n.a.

n.a.

n.a.

n.a.

30

750

5

0.34

14

0.97

n.a.

n.a.

n.a.

n.a.

36

900

5

0.34

14

0.97

n.a.

n.a.

n.a.

n.a.

US
Patent numbers: 4236648 and other international patents. TEF liner
available for disk sizes 2” and larger. JRS teeth ring attached to the
disk is 316SS. Other materials upon request. Minimum burst pressures are
applicable at all temperatures, maximum burst pressures are at 72°F
(32°C). For burst pressures below JRS minimums use the FRS type disk. For
Pressures above the JRS maximums use disk types S-90, RLS, SKR, and Sigma.
Hastelloy is a trademark of Haynes International Inc., Monel and Inconel
are trademarks of Inco Alloys International, Inc.

A domed,
low-pressure frustum-shaped, reverse buckling disk, the FRS reverses on
overpressure and opens along a pre-weakened circular score line on the
downstream side of the disk. The circular score line has an interupted
“hinge” segment which retains the disk’s central petal and prevents
fragmentation.

Burst
Alert Sensors are installed downstream of the Rupture Disk (Bursting Disc) device and
provide a convenient means of generating an electrical signal when
appropriately integrated into plant control systems, or connected to the
BS&B Safety Systems Burst Disk Monitor. The Burst Alert Sensor is a
“membrane switch” that changes from closed circuit to open circuit when
the upstream Rupture Disk (Bursting Disc) (or relief valve) opens. Consult BS&B for
proper sensor selection and specification. (Refer to catalog 77-1012 for
more information.)

Safety
Heads
SRB-7RS™, S90-7R™ and SRB-7FS™

Three
asymmetric locating pins ensure centering and correct orientation of the
disk within the Safety Head

A
"bite-type" seal for sizes 2" (50mm) and larger engages with the disk
flange creating a metal-to-metal 'bubble tight' seal

Disk
dome protected by Safety Head inlet

Maximized flow with full circular opening

Flow
arrows indicate direction of flow

Special configurations available

S90-7R™ Pre-
Assembled Safety Head

Locates
inside the studs between two companion flanges.

Offers
pre-assembly of S-90 or FRS disks into the Safety Head before installation
into the pressure system.

Disks
cannot be reinstalled into the pressure system with a pre-assembled Safety
Head. The disk would not seat within the Safety Head in the same manner
each time risking leakage and compromising service life.

Standard
Materials:
316 Stainless Steel and Carbon Steel.

Size Type S90-7R

Safety Head Flange Rating

Face-to-Face Dimensions

in

mm

ANSI

DIN

JIS

in

1

25

150

10/16

10/16

1.250

1

25

300/600

25/40

20/30/40

1.250

1

25

900/1500

-

-

1.750

1.5

40

150

10/16

10/16

1.250

1.5

40

300/600

25/40

20/30/40

1.250

1.5

40

900/1500

-

-

1.440

2

50

150

10/16

10/16

1.250

2

50

300/600

25/40

20/30/40

1.250

2

50

900/1500

-

-

1.620

3

80

150

10/16

10/16

1.376

3

80

300/600

25/40

20/30/40

1.500

3

80

900

-

-

1.750

4

100

150

10/16

10/16

1.719

4

100

300

25/40

20/30/40

1.719

4

100

600

-

-

1.719

6

150

150

10/16

10/16

2.500

6

150

300

25/40

20/30/40

2.500

6

150

600

-

-

3.125

8

200

150

-

-

3.375

8

200

300

-

-

3.375

10

250

150

-

-

6.000

10

250

300

-

-

6.000

12

300

150

-

-

5.688

12

300

300

-

-

5.500

14

350

150

-

-

5.625

14

350

300

-

-

5.625

16

400

150

-

-

6.375

16

400

300

-

-

7.125

18

450

150

-

-

7.500

18

450

300

-

-

7.500

20

500

150

-

-

6.250

20

500

300

-

-

8.625

24

600

150

-

-

7.000

24

600

300

-

-

7.750

30*

750

-

-

-

12.000

36*

900

-

-

-

15.000

*30” and
36” torque value applies to MSS SP-44 Class 150 flanges
Hastelloy is a
trademark of Haynes International Inc., Monel and Inconel are trademarks
of Inco Alloys International, Inc.

SRB-7RS™
Pre-torqued Safety Head

The
original pre-torqued Safety Head, the SRB-7RS allows proper clamping of a
Rupture Disk (Bursting Disc) to be completed in the workshop before installation between
companion flanges. A disk installed in a pre-torqued type SRB-7RS Safety
Head may be taken out of service, inspected, cleaned (if appropriate) and
reinstalled provided the cap screws are not loosened and the torque value
is maintained.

Locates
inside the studs between two companion flanges.

A J-bolt
ensures the Safety Head is fitted in the required direction between
companion flanges by engaging a blind hole drilled on the inlet companion
flange perimeter. The J-bolt provides a constant visible signal of correct
installation.

Full-bolted option sharing the design features of the type SRB-7RS
Safety Head. The type SRB-7FS Safety Head installs between companion
flanges with the studs passing through bolt holes in the perimeter of the
holder.
Recommended for RTJ, tongue and groove flange facings, or for a
Safety Head in Nickel Alloy 200 or Tantalum (above 1 1/2", 40mm
size).

Standard
Materials:
316 Stainless
Steel and Carbon Steel. Also available in Nickel Alloy 200 and
Tantalum.

Products, specifications and all data in this literature are
subject to change without notice. Questions regarding product selection
and specifications for specific applications should be directed to
BS&B Safety Systems, Inc. or BS&B Safety Systems Ltd.

All
sales are subject to BS&B Safety Systems, Inc. or BS&B Safety
Systems, Ltd. standard terms and conditions of sale. Nothing herein should
be construed as a warranty of merchantability or fitness for a particular
purpose.